What is the chemical symbol for water?

Which of these is a renewable source of energy?

What is the main function of the human heart?

Which gas is essential for photosynthesis?

What type of reaction is burning of methane gas?

Which part of the human eye controls the amount of light entering?

What is the process called when a solid directly changes into a gas?

Which of the following is an example of a non-metal?

Which of the following is responsible for carrying oxygen in the blood?

What is the unit of electric current?